1. Field of the Invention
The present invention is related to a tractor-trailer combination vehicle, and more particularly, to a device for controlling the brake of the trailer for the purpose of suppressing side sway of the trailer.
2. Description of the Prior Art
In a tractor-trailer combination vehicle in which a trailer is connected with a tractor by a pivotable joint which allows the trailer to sway around the vertical pivot axis of the joint relative to the tractor, it often occurs that, when the combination vehicle receives a side wind during a running or the driver turns the steering wheel at a high rate, the combination vehicle makes an oscillatory side swaying by alternately changing the angle between the longitudinal axes of the tractor and the trailer, the angle being generally called "hitch angle". Such a side sway of the trailer is of course not desirable, as it could induce the so-called jack knife of the combination vehicle when it exasperates.
As a joint for the tractor and the trailer equipped with a means for controlling the side sway of the trailer, there has been proposed by Japanese Patent Laid-open Publication 51-108419 a joint which, when the tractor is braked with a substantial lateral biasing of the trailer relative thereto, actuates the brake of the trailer by utilizing a compression force acting therethrough due to the inertia of the trailer, so as to apply an unbalanced braking force to the opposite side wheels of the trailer, thereby generating a turning moment in the trailer which acts to suppress a side sway of the trailer relative to the tractor.
When the trailer is connected with the tractor by such a joint, an anti-sway moment will be automatically generated in the trailer when it sways relative to the tractor, provided that a compression force is applied through the joint by the tractor being braked while the trailer would outrun the tractor due to its inertia.
However, in the above-mentioned prior art joint, no anti-sway moment is generated in the trailer when there are no compression forces through the joint. Therefore, such a prior art joint is not effectively usable in a tractor-trailer combination vehicle in which the normal braking action is applied to both the tractor and the trailer.